Category Archives: Sensitivity & feedbacks

Simplicity amidst complexity (?)

by Judith Curry

Isaac Held’s new article in Science raises some interesting questions.

Continue reading

Climate sensitivity: technical discussion thread

by Judith Curry

The Lewis and Crok paper is stimulating much discussion; unfortunately little of it is technical.  Lets devote a thread to technical discussion on the issues the raise.

Continue reading

Lewis and Crok: Climate less sensitive to CO2 than models suggest

by Judith Curry

Nic Lewis and Marcel Crok have published a new report on climate sensitivity.

Continue reading

Seasonal radiative response

by Steve McGee

In science, one likes to have more examples than theories. – Dusan Djuric

Continue reading

CO2 ‘control knob’ fallacy (?)

by Judith Curry

Previous IPCC reports — and much of the debate over how to react to them — have appeared to treat the Earth’s climate as if it were a domestic central heating system, with carbon emissions analogous to the dial on the thermostat: a small tweak here will result in a temperature rise of precisely 0.2°C and so on. – The Spectator

Continue reading

Nic Lewis on the UK Met Office on the pause

by Nic Lewis

These comments constitute a response to erroneous statements and misrepresentations made in a report published by the Met Office in July 2013: “The recent pause in global warming (3): What are the implications for projections of future warming?” (the Report).

Continue reading

Tall tales and fat tails

by Judith Curry

The economic value of climate mitigation depends sensitively on the slim possibility of extreme warming.

Continue reading

Mainstreaming ECS ~ 2 C

by Judith Curry

Humanity has a second chance to stop dangerous climate change. Temperature data from the last decade offers an unexpected opportunity to stay below the agreed international target of 2 °C of global warming. – New Scientist

Continue reading

DocMartyn’s estimate of climate sensitivity and forecast of future global temperatures

by DocMartyn

My forecast is that temperatures will remain flat until 2040.

Continue reading

Meta-uncertainty in the determination of climate sensitivity

by Judith Curry

Two heavyweight climate scientists have published very different ideas about how much the Earth is going to warm in the coming decades. – Washington Weather Gang

Continue reading

The Forest 2006 climate sensitivity study and misprocessing of data – an update

by Nicholas Lewis

Some of you may recall my guest post at Climate Etc last June, here, questioning whether the results of the Forest et al., 2006, (F06) study on estimating climate sensitivity might have arisen from misprocessing of data.

Continue reading

UK MSM on climate sensitivity

by Judith Curry

If climate scientists were credit-rating agencies, climate sensitivity would be on negative watch. But it would not yet be downgraded. – The Economist

Continue reading

New perspectives on climate sensitivity

by Judith Curry

Here is a summary of some important new papers on the topics of climate sensitivity and attribution.

Continue reading

Sensitivity about sensitivity

by Judith Curry

. . . the IPCC’s sensitivity estimate cannot readily be reconciled with forcing estimates and observational data. – James Annan

Continue reading

Climate sensitivity in the AR5 SOD

by Judith Curry

By far the most important debate about climate change is taking place among scientists, on the issue of climate sensitivity: How much warming will a doubling of atmospheric carbon dioxide actually produce?  - Matt Ridley

Continue reading

Clouds and MAGIC

by Judith Curry

Ocean clouds obscure warming’s fate, create ‘fundamental’ problems for models. – Paul Voosen
.

Sensitivity of the nocturnal boundary layer to added longwave radiative forcing

by Judith Curry

So, if you increase the longwave radiative forcing from CO2, which of the following happens?

  1. heating of the near surface ground temperature
  2. heating of the atmosphere
  3. heating of the deep ground temperature
  4. the heat is lost to radiative emission from the skin surface.

Continue reading

Questioning the Forest et al. (2006) sensitivity study

by Nicholas Lewis

Re:  Data inconsistencies in Forest, Stone and Sokolov (2006)  GRL paper 2005GL023977 ‘Estimated PDFs of climate system properties including natural and anthropogenic forcings

Continue reading

Climate sensitivity discussion thread

by Judith Curry

There are several recent estimates of climate sensitivity that are worth taking a look at.

Continue reading

21st century solar cooling

by Judith Curry

During the 20th century, solar activity increased in magnitude to a so-called grand maximum. It is probable that this high level of solar activity is at or near its end. It is of great interest whether any future reduction in solar activity could have a significant impact on climate that could partially offset the projected anthropogenic warming. (Jones et al. 2012).

Continue reading

Nonequilibrium thermodynamics and maximum entropy production in the Earth system

by Judith Curry

Albert Einstein on thermodynamics:

A theory is more impressive the greater the simplicity of its premises, the more different are the kinds of things it relates, and the more extended its range of applicability. Therefore, the deep impression which classical thermodynamics made on me. It is the only physical theory of universal content, which I am convinced, that within the framework of applicability of its basic concepts will never be overthrown.

Continue reading

Another IPCC error: cloud albedo forcing

by Paul Matthews

Climate Etc has discussed the IPCC’s new protocol for alleged errors and an error found by Nic Lewis regarding climate sensitivity. This post discusses another error in IPCC AR4, one that has been around for some time but has only recently been reported to the IPCC.

Continue reading

WHT on Schmittner et al. on climate sensitivity

by WebHubTelescope
.
Schmittner et al have written a paper titled “Climate Sensitivity Estimated from Temperature Reconstructions of the Last Glacial Maximum” (Science Nov 24. 2011).

Feedback in climate

by Chris Colose

There has been a lot of blog interest recently on feedback theory and climate sensitivity (e.g., Isaac Held, ClimateAudit, Science of Doom, Nick Stokes, one on control theory here at Climate Etc.).

Continue reading

CO2 control knob technical discussion thread

by Judith Curry

The original thread for Andy Lacis’ post got derailed by non-technical comments.  This thread is STRICTLY for technical comments (heavy moderation will be imposed); make your general comments on the original thread.